[Evaluation of the bone marrow in patients with brucellosis. Clinico-pathological correlation]

In the present study the 60 patients with brucellosis and evaluation of bone marrow aspirate seen at the Hospital Base Cayetano Heredia from 1980 to 1986 were included. Iron deficiency was found in the bone marrow in 34.5% of patients, 31% in males and 36% in females. No correlation was found between iron deficiency and severity of the hematological or non-hematological clinical features. Bone marrow cytophagocytosis was found in 28.3% of patients. All had moderate to severe clinical features, and it is postulated that this finding may be helpful as a severity marker in patients with brucellosis. Bone marrow cytophagocytosis was significantly associated with the presence of hematologic abnormalities in general; anemia was the most common of these, followed by thrombocytopenia. This finding suggests that cytophagocytosis is an important mechanism in the pathogenesis of these abnormalities in brucellosis. Bone marrow hypercellularity was present in 70% with normocellularity in 28.3% and one case of pure megakaryocytic aplasia. In thirty-five patients pathological study of bone marrow was carried out 10 of these (28.5%) had granulomas. Their presence was not correlated with the clinical severity. Peripheral blood finding were: anemia in 83.3%, with two cases of hemolytic anemia and positive direct Coombs test, one of them associated with thrombocytopenia (Evans syndrome); leukopenia in 21%, basically due to neutropenia; thrombocytopenia in 33.3%, in one case associated with positive antiplatelet antibodies and with pure megakaryocytic aplasia in others; pancytopenia in 13.5% of cases (8 patients) associated to bone marrow cytophagocytosis in 5 cases (64.5%) and thus suggesting that this might be the major underlying pathogenetic mechanism.